The unicast relayed packet cames from 10.8.3.23 to 10.8.8.71, but the response go to the relayed agent ip 192.168.2.x... then have sense a route is needed.

This morning i connect this switch to our network: both switch and dhcp server have same gateway: 10.15.255.254. 10.15.255.254 is a router with a static route to 192.168.2.0/24 --> 10.8.3.23 (test-switch)

because the discover is sent from the switch, the offer should be sent back to the switch. It is not, due to the gateway being pointed to the firewall/router. Probably the router drops the packets, or the switch drops it because it is coming from the firewall/router.

Either use your router as gateway for the other vlan, or configure static routes on the DHCP router. I you configure it as persistent (route add -p ) you should not have to configure a batch file.

Wireshark on DHCP server shows that server dont send Offer unless persistent route is added, the offer is not rejected, symply is not sended.

The router are two switches with VLAG and VRRP at core layer, the problem is we reach the limit of 15 VRRP interfaces at core layer and more vlans are required, the only way i see is make local vlans on avaya access switch stacks and let the stack do the high avaliability of gateway (dirty solution, some vlan will have gateway on core layer and some will have gateway on access switch)

Tomorrow i try to remove vlan 1 and add other vlan to force symetric route (swicth and dhcp server not in same vlan).